Southwestern Region Of Bangladesh Research Articles

Assessing White Spot Syndrome Virus (WSSV) and Acute Hepatopancreatic Necrosis Disease (AHPND) concurrent with Vibrio spp. in various Penaeus monodon aquaculture farms at southwestern region of Bangladesh

This study was conducted to assess the prevalence of White Spot Syndrome Virus (WSSV) and Acute Hepatopancreatic Necrosis Disease (AHPND) in giant tiger shrimp (Penaeus monodon Fabricius, 1798) aquaculture systems (extensive, improved-extensive, and semi-intensive) in the south-western region of Bangladesh. This research employed real-time polymerase chain reaction (RT-PCR) to quantification cycle (Cq) values for identification of WSSV and AHPND in shrimp samples and Vibrio spp. was identified through biochemical tests on water and soil samples (n=72 for each) from different aquaculture systems. The results of the study indicated significant difference (p < 0.05) in nitrate and ammonia levels across the various aquaculture systems, highlighting the critical need for rigorous water quality monitoring and management. Extensive aquaculture exhibited the highest prevalence of WSSV (40%) and AHPND (33%) positive samples, whereas semi-intensive aquaculture had the lowest prevalence, with 22% WSSV-positive and 20% AHPND-positive samples. Biochemical analysis identified three Vibrio spp. such as V. cholerae, V. vulnificus, and V. parahaemolyticus - with significantly higher concentrations in extensive aquaculture compared to semi-intensive. Notably, V. vulnificus was more abundant (0.9×103 cfu/ml) in the soil of extensive aquaculture, while it was less prevalent in water. In conclusion, this study underscores that the risk of WSSV and AHPND was greater in extensive aquaculture due to inadequate management.

Impacts on Aquatic Life for Indiscriminate Exploitation of Baby Shrimp (P. monodon) in the Coastal Area, South-Western Region of Bangladesh

Fishing for baby shrimp (Penaeus monodon post-larvae) is a major source of income for most fishermen in the coastal regions of the southwestern part of Bangladesh during during July, 2022 to June, 2023. These post-larvae collectors lack financial security and are socially regressive. Other aquatic species are destroyed by the indiscriminate exploitation of baby shrimp for aquaculture. According to the present study, about 98-99% of other larvae are destroyed to catch nearly 1-2% of indiscriminate exploitation baby shrimp in our study area where averagely 0.35% Penaeus indicus, 0.06% Penaeus merguiensis, 0.037% Metapenaeus Monoceros, 3.58% Other shrimp, 6.59% Fin-fish larvae, 5.95% Crab larvae, and 82.42% Small organisms. Actually, the government of Bangladesh already has declared a ban period and illegal baby shrimp catching. But to maintain the poor fisherman's livelihood, they are doing that continuously. Furthermore, because wild baby shrimp are said to have a far higher survival rate than baby shrimp raised in hatcheries, farmers prefer wild baby shrimp. For thousands of Bangladeshi coastal landless and jobless poor people, wild prawn baby shrimp fishing has created employment opportunities. This study describes the impact of wild baby shrimp fishing in coastal areas of Bangladesh.

Farmers’ motivational factors for medicinal plant production in the southwestern region of Bangladesh

Medicinal plants (MPs) generate cash income and save millions of people in Bangladesh. The aim of this study is to identify farmers’ motivational factors to cultivate MPs. This study is based on primary data collected from 196 sample households from two MP-growing districts of Bangladesh. Three MPs, namely, Aloe vera, Bombax ceiba, and Withania somnifera, were considered for this study. Principal component analysis (PCA), the z test, the Wilcoxon signed-rank test and factor analysis (FA) were used in this study. The results showed that household size and male-headed household status are driving socioeconomic factors. Ownership of water pumps, number of rooms in the house, access to contract marketing, and off-farm income are significant economic factors encouraging households to cultivate MPs. Farming experience, scientific knowledge, access to high land and access to loamy land are significant biophysical factors motivating farmers to cultivate MPs. More technical support and institutionalized contract marketing systems should be continued and established for the sustainability of MP cultivation.

Effect of grazing hour on growth performance of crossbred sheep from southwest coastal region of Bangladesh

Sheep are small ruminants that require small amounts of feed and can graze on poor-quality pastures, including fallow lands, roadsides, dikes and playgrounds. Therefore, the experiment was conducted to evaluate the effect of the grazing length on growth performance of crossbred sheep in the southwestern region of Bangladesh. Sixteen crossbred female sheep were divided into four treatment groups and randomly allowed four different grazing periods. The experimental design was based on a randomized complete block design (RCBD). Lambs were initially weighed and grouped by keeping the average weight of the four treatment groups approximately the same. The grazing hours allocated to the four treatment groups were 6, 8, 10 and 12 hours, respectively. During this period, the sheep of particular treatment groups were housed when their allocated grazing period was completed. Empty body weight data were taken fortnightly in the morning before they were allowed to graze. The results revealed that body weight increased with increasing grazing length but the mean difference did not differ significantly (p&gt;0.05). In most cases, the highest body weight was observed in sheep grazing for 12 hours per day. Average growth rates of grazing sheep varied significantly between the 6 to 8 hour and 10 to 12 hour grazing groups. But between the 6 to 8 hour grazing group and the 10 and 12 hour grazing group, the growth rate of crossbred sheep did not vary significantly (p&gt;0.05). The growth rate (g day-1) of crossbred sheep ranged from 22.44±4.75 to 92.00±11.95, highest in 12 hour grazing group and lowest in 6 hour group. It can be concluded that the body weight and growth rate of crossbred sheep increased with an increase in grazing length. However, 10 hours of grazing meets the requirements for their maintenance and growth due to good pasture quality. Int. J. Agril. Res. Innov. Tech. 14(1): 104-107, June 2024

An investigation on the performance of rice threshing drums in the southwestern region of Bangladesh

This study evaluated the performance indices of the locally developed rice-threshing drum in the Khulna region of Bangladesh. Threshing efficiency, throughput capacity, output capacity, threshing capacity and grain to straw ratio were assessed and data were analyzed using ANOVA as a statistical tool. The study involved the thresher with different engine horsepower capacities (25hp, 20hp, and 16hp). The variables of paddy were two stages of moisture content (14% referred as dry condition and 23% referred as wet condition), four different cutting heights of paddy (25-30, 30-35, 35-40 and 40-45 cm). The values for threshing efficiency, threshing capacity, output capacity, throughput capacity and grain to straw ratio in dry conditions ranged from 97.83 – 98.83%, 1700-2373 kg/hr, 27.75 -36.46 kg/hr, 930 – 1436 kg/hr and 1.21-1.54 respectively and in wet condition ranged from 96.15 – 97.79%, 1168-2167 kg/hr, 41.64 -49.99 kg/hr, 622 – 1280 kg/hr and 1.14-1.45, respectively. It was observed that with the increase in moisture content, cutting height and decrease in engine horsepower, there was a significant decrease (p &lt; 0.05) in output capacity, threshing capacity, threshing efficiency and grain to straw ratio and vice versa. Therefore, the thresher used would be more useful by maintaining a proper combination of machine-crop parameters such as a moisture content of 14-15 %, an engine horsepower of 25 hp and a cutting height of 25-30 cm. Insights from this study can guide the development and adoption of improved paddy-threshing technologies in the region.

Investigation on parasitic infestation of Labeo rohita (Hamilton, 1822) in the south-western region of Bangladesh.

Our investigation focused into Labeo rohita, commonly known as Rui, a freshwateraquatic species in Bangladesh. Despite their nutritional significance, these fish faced a pressing challenge: parasite infections threaten the economic stability of the aquaculture sector. The present study aimed to investigate the parasite and histological changes in major organs of L. rohita, collected fromKhulna region - Dumuria, Paikgacha and Rupsha. About 180 (30/month) specimens were collected between the month of March and August 2023 to observe the parasitic status in L. rohita. Through microscopic examination, a total of 323 parasites were uncovered, spanning categories including Cestode, Nematode, Acanthocephala, Trematode and Digenia, predominantly residing in the intestines of L. rohita. The highest prevalence rate (70%) was recorded in both March and May 2023, with peak mean intensity observed in July (3.73). Notably, the highest mean abundance (2.37) exhibited in July and index of infestation (45.34) in June. Histological analysis confirmed parasitic infestations in the gastrointestinal region, with displaying histological changes within major organs such as the liver, kidney, gills, spleen and testicles due to parasitic infection. This study concluded that the indentified six categories of parasite and the affect of parasitic infestation in major organs of L. rohita within the study period. Urgent efforts to implement effective strategies for controlling the parasite infections in aquaculture to ensure the sustainable production of this invaluable fish species.

Food insecurity and its contributing determinants among rural households in the south-western region of Bangladesh, 2021: A cross-sectional study

IntroductionThe onset of the COVID-19 pandemic has disrupted food access, resulting in substantial consequences for food insecurity and contributing to adverse individual and public health outcomes. To comprehensively evaluate these challenges and grasp their implications for food security, this study aimed to evaluate the contributing determinants of food insecurity among rural households in the southwestern region of Bangladesh. Study designA cross-sectional study was conducted using a validated questionnaire in selected 310 rural household respondents from the southwestern region of Bangladesh. MethodsHousehold food insecurity status was the outcome variable for the analysis. Multinomial logistic regression analysis was used to explore and predict risk factors correlated with food insecurity among southwestern Bangladeshi households. ResultsWe found that 59 % and 27.5 % of households were suffering from moderate food insecurity and severe food insecurity, respectively. The multinomial regression model revealed that respondents residing in Kusthia (RRR = 5.56 CI:2.67–8.4 and RRR = 6.65, CI:3.37–9.22) aged between 30 and 40 years (RRR = 2.32, 95 % CI:1.84–3.77 and RRR = 1.87, 95 % CI:1.48–3.97) and 40–50 years (RRR = 1.86 95 % CI:1.46–3.82 and RRR = 1.95, 95 % CI:1.75–3.26) were significantly associated with mild-to-moderate and severe food insecurity. Respondents with a monthly family income of <58.96 USD (3.38 times and 2.18 times), had ≥5 family members (2.68 times and 1.89 times), and had poor income during the pandemic (4.25 times and 2.75 times) more likely to be moderate and severe food insecure. ConclusionThe results emphasized that during the COVID-19 lockdown in Bangladesh, rural households faced diverse levels of food insecurity, ranging from moderate to severe. It suggests that efforts to raise awareness and implement support strategies for those at higher risk should not only focus on income but also consider additional factors such as family size, adults aged 30–40 years, and occupation.

Land subsidence monitoring using InSAR technique in the southwestern region of Bangladesh

Deltas like the Ganges-Brahmaputra Delta (GBD) experience significant land subsidence due to overlaying load, consolidation, sediment compaction, regional tectonics, and human activity. The southwestern region of Bangladesh, marked by its low-lying floodplain with compressible sediments, experiences significant land subsidence. However, accurate assessments for these areas are very scarce, often focusing on the point-based measurements. This study employed Interferometric Synthetic Aperture Radar analysis, spanning from 2014 to 2022, to effectively measure land subsidence, and visualize it spatially. In the study area, subsidence rates were found to be ranging from 3 to 20 mm/year, with most areas experiencing 3-10 mm/year. While some areas show higher rates of 10-13 mm/year, very few exceeded 14 mm/year. The average subsidence rate was 5.98 mm/year, demonstrating significant spatial variability, with higher rates in Gopalganj, Patuakhali, Bhola, Barishal, and other areas. The findings were validated based on existing Global navigation satellite system (GNSS) data points, affirming their reliability. Despite minor discrepancies with other measurements at specific points, the overall results align well with existing data. This comprehensive analysis provides a detailed assessment of land subsidence in the southwestern region of Bangladesh, highlighting significant spatial variability and offering valuable insights for future coastal development and risk mitigation strategies.

OFF-SEASON AGRONOMIC PERFORMANCE OF THREE EXOTIC WATERMELON VARIETIES IN THE SOUTH-WESTERN REGION OF BANGLADESH

The watermelon [Citrullus lanatus (Thunb.)] - a herbaceous, annual, and monoecious fruit - belongs to the family Cucurbitaceae and is usually cultivated in Bangladesh during the period from February to April. However, they may be grown year-round, and off-season watermelon cultivation is more profitable than seasonal farming. The research was conducted at the Field Laboratory of Khulna University from August to December, 2021 to evaluate the off-season agronomic performance of the selected three watermelon varieties viz. Kanya, Black Super, and Tripti. The experiment investigated both the vegetative and reproductive growth of watermelon following a Randomized Complete Block Design with five replications. Kanya had the longest vines with the most leaves, and nodes followed by Black Super and Tripti. All the watermelon cultivars were found to be similar in producing male flowers, while Black Super and Kanya produced more female flowers, and Black Super also produced the highest fruit yield (6.37 t ha-1), which was statistically similar to Kanya (5.84 t ha-1) and the lowest yield was obtained from Tripti (3.69 t ha-1). Kanya performed better regarding fruit length (22.47 cm), fruit width (30.89 cm), and fruit weight (1.03 kg). Black Super scored the highest TSS (8.43) (Brix0) value, followed by Kanya (7.63) and Tripti (6.39). The amount of weight loss after the harvesting of fruits was less in Black Super, followed by Kanya and Tripti. Black Super had a longer recorded shelf life (28 days) than the other two varieties. The results of this study suggest that Black Super and Kanya can be grown during the off-season in the south-western region of Bangladesh.

Floating Market-Based Slow Tourism: Harnessing Climate-Based Entrepreneurship towards Community Development in the South-Western Region of Bangladesh

Purpose: Slow tourism is a new, alternative form of tourism competing with mass tourism, as tapping its full potential can be utilised in riverine and flood-prone countries. The key purpose of this study is to find the elements of slow tourism in the southwestern part of Bangladesh, known for its serene floating market, and assess its features that are compatible with the principles of slow tourism. &#x0D; Methodology: This research adopted a qualitative approach. Qualitative methods such as narrative interviews, key informant interviews and FGDs were used to collect primary data. The southern region of Bangladesh, is famous for floating market and was selected as a study site.&#x0D; Findings: To incorporate the floating market through the broader lens of “Slow Tourism”, synthesising the attributes of slow tourism was significant. As the attributes of the floating market supported the characteristics of slow tourism to a certain degree, the floating markets and adjacent areas were a suitable premise for developing the concept of slow tourism.&#x0D; Originality: Since there hasn’t been ample research on slow tourism in Bangladesh, this study can transform the perception of conventional tourism into alternative tourism. It provides tourists with spiritual tranquillity in the desired destinations of floating markets and a leeway to connect with local people, history and cultural products rendering a mutual reciprocity for future research.

Microplastics and heavy metals in freshwater fish species in the southwestern region of Bangladesh: An emerging concern for public health

Microplastics (MPs) pollution and its associated toxicity raising concerns among scientists as a result of their toxicological impacts on human health and the ecosystem. This study aims to investigate the microplastics and heavy metals (HMs) contamination in seventeen freshwater fish species collected from the Southwestern region of Bangladesh. Microplastics extracted from these species using the hydrogen peroxide digestion method and characterized by Attenuated Total Reflection- Fourier Transform Infrared Spectroscopy (ATR-FTIR). Atomic Absorption Spectrometry (AAS) was used to determine the concentration of HMs in different species for evaluating human health risks. A total of 142 microplastic particles were extracted with an average concentration of 1.13 ± 0.84 items per individual of fish, where the highest microplastics were found in C. punctata (3.43 ± 3.15 items) and lowest in A. mola (0.14 ± 0.38 items). Identified microplastics were dominated by < 1 mm size (87.3%), black color (60.6%), and fiber shape (94.4%). Polyethylene (73.08%), polypropylene (21.15%), and polystyrene (5.77%) were the most prevalent among the identified microplastic polymers. A positive correlation was found between microplastic numbers and fish weight and length. Low to moderate human health risks were associated with microplastics. The concentration (mg/kg) of heavy metals in studied fish samples was Cr (0.47–2.89; 0.79 ± 0.56) > Cu (0.01–1.14; 0.50 ± 0.44) > Pb (0.04–0.58; 0.22 ± 0.12) > Cd (0.00–0.11; 0.03 ± 0.03), respectively. Heavy metals-based human health risk assessment results show that there are no major non-carcinogenic health risks (THI<1), while higher carcinogenic risks are present for consumers.

Hydro-chemical characteristics and groundwater quality evaluation in south-western region of Bangladesh: A GIS-based approach and multivariate analyses

The study focuses on the chemistry of groundwater and if it is suitable for drinking and for use in agriculture using water quality indices, GIS mapping, and multivariate analyses in Sharsa Upazila, Jashore district, Bangladesh. In this study, the concentration of NH4+, K+, Ca2+, EC, Turbidity overstep BDWS drinking standards in 69 %, 14 %, 100 %, 40 % (WHO), 73 % of samples respectively. The value of Water Quality Indices (WQI) results inferred that the maximum specimen was held good quality for drinking uses, and the values distributed central eastern part to the south-eastern part were good quality water in the selected studied area. The study area's PH, EC, SAR, Na (%), TH, and NO3− values were mapped using GIS tools to show their spatial distribution. The cluster and correlation matrix analyses are used to validate for Principle Component Analysis (PCA). The five PCA results exhibited that the presence of EC, turbidity, K+, SO42− and NO3− was significant and was caused by both geogenic (rock weathering and cation exchange) and anthropogenic (agrochemicals, animal feedback) factor. According to the hydro-geochemical data, the maximum number of samples is of the Ca–Mg–HCO3–Cl type and is dominated by rocks. The irrigation water indices like MH, KR, SAR, and %Na indicate show high-quality groundwater for irrigation purposes. Most of the samples were satisfactory and compiled with WHO and Bangladeshi criteria for standard drinking water guideline values.

The production and reproductive traits among different goat breeds in southwestern region of Bangladesh

In Bangladesh, a comprehensive study was conducted over one year to compare the reproductive and productive performance of Black Bengal, Jamunapari, and crossbred goats. The study involved a sample size of 226 goats and provided insightful information on the distinctive capabilities of each type of goat breeds. Most of the doe were 21–30 months of age, and their weight was 21–30 kg. The feed supply for the doe was concentrated green grass, whereas the kids got supplementary feed like rice bran. Among the reproductive traits, age at puberty, age of first kidding, and age of the first conception were significantly (P&lt;0.001) higher in Jamunapari goats, whereas aerial kidding intervals were found in 263.77 ± 54.26 days in crossbreeds. Postpartum heat periods were highest at 68.50 ± 5.53 days in Jamunapari goats at 1st and 2nd parity, though at 3rd parity, 22.96 ± 26.66 days were uppermost in Black Bengal. There was no significant effect of parity on lactation length or milk production. Though Jamunapari goats show the highest lactation length at 1st and 2nd parity, at 3rd parity, 2.56 ± 2.89 kg was the largest in Black Bengals. The mortality of kids was high in the second parity in Black Bengal and crossbreeds, whereas in Jamunapari, it was higher in the first and second parities. The mortality rate of kids under 20 days was high, which gradually decreased with the advancement of age. Different periparturient and postpartum diseases, like abortion, dystocia, retained placenta, etc., decreased the reproductive performance of goats. The Black Bengal goat exhibited superior productive and reproductive performance to Jamunapari and crossbred goats. The study's findings suggest that, in the southwestern region of Bangladesh, prioritizing Black Bengal goats for breeding programs could potentially enhance both productive and reproductive traits compared to Jamunapari and crossbred goats. Asian Australas. J. Biosci. Biotechnol. 2023, 8 (3), 78-87

IMPACT OF WATERLOGGING ON LAND USE, BIODIVERSITY AND ECOSYSTEM SERVICES IN TALA UPAZILA, BANGLADESH

Waterlogging has become a major issue due to its severe impact on the south-western region of Bangladesh. This study aims to assess the trend of waterlogging and to find out the impact of waterlogging on land use, biodiversity and ecosystem services in the Tala located in the south-western region of Bangladesh. Satellite images of 1990, 2000, 2010 and 2021 were analyzed to portray the trend of waterlogging and questionnaire survey, FGDs and KIIs were used to discover the impacts of waterlogging on land use, biodiversity and ecosystem services in the study area. Satellite image analysis has shown that there is an ascending trend (increased by 154.5% between 1990 and 2000, by 135.9% between 2000 and 2010 and by 23.6% between 2010 and 2021) of waterlogging in the Tala upazila. Qualitative investigations revealed that waterlogging due to siltation in the associated rivers and unplanned human interventions, has been posing threats to the crop lands by turning them marshy. Biodiversity of aquaculture species, agricultural crops, aquatic wild animals, livestock, trees, birds etc. have been severely affected by waterlogging. Waterlogging is highly responsible for the low production of crop and aquaculture species, shortage of safe drinking water, habitat loss, sanitization, migration of people and so on.

Bacteriophage and non-pathogenic Vibrio to control diseases in shrimp aquaculture

The study aimed to address the recurring outbreaks of microbial diseases in shrimp aquaculture in Bangladesh the study focused on the utilization of bacteriophages and non-pathogenic Vibrio. The bacteriophages were isolated from sewage water sample collected from shrimp farm, hatchery, and the JUST campus. The bacteriophages were tested for their ability to infect different Vibrio strains in order to assess their bacteriolytic activity. Non-pathogenic Vibrio strains were obtained from suspected diseased isolates collected from the south-western region of Bangladesh through PCR amplification. In laboratory tests, the bacteriophages successfully infected 91 % of the tested Vibrio strains (19 out of 21 strains). In the experimental unit, shrimp treated with phage prophylaxis and phage treatment demonstrated notable protection against AHPND and was able to survive a deadly bacterial challenge. A total of 35 suspected diseased isolates were tested, and PCR amplification revealed 6 non-pathogenic Vibrio strains. In field trials, cultured bacteriophages were applied at a concentration of 1.5×106 PFU/ml, while non-pathogenic Vibrio was applied at 5×105 CFU/ml. The trials showed increased protection against infections and no severe deaths during the adaptive research phase. The cultured shrimp were analyzed morphologically and showed a muscle gut ratio greater than 4:1. No abnormal deformities were observed in their appendages or overall body, suggesting their overall health and well-being. The bacteriological tests conducted on the shrimp samples (application of bacteriophages and non-pathogenic Vibrio) revealed that 18 % of them were infected with bacteria, primarily Vibrio cholerae, Vibrio parahaemolyticus, and other bacterial species. Despite this, the infections did not lead to a disease outbreak; PCR amplification showed negative results for AHPND, White Spot Syndrome Virus (WSSV), and Enterocytozoon hepatopenaei (EHP). The results highlight the potential of using bacteriophages and non-pathogenic Vibrio as a sustainable solution for preventing and controlling microbial diseases in shrimp aquaculture. Furthermore, this study will contribute valuable insights into the development of alternative strategies to combat antibiotic resistance and promote the growth of the shrimp industry in Bangladesh.

Measuring the level of rurality in the Southwestern region of Bangladesh

This research intends to measure and characterize the level of rurality in the southwestern region of Bangladesh using an indexing approach from functional perspective. The findings of the study can be conducive for efficient decision making related to rural development policies and planning. Besides, operational delineation of administrative units, such as Unions and Wards, is essential for the formulation and effective implementation of evidence-based development initiatives. The study has utilized the latest available population census data published by Bangladesh Bureau of Statistics (BBS). The results reveal that Satkhira district exhibits a higher degree of rurality (RI = 4.23) compared to Khulna (RI = 3.58) and Bagerhat (RI = 4.14) districts. This variation among the three districts is ascribed to existing rural–urban disparities. The study underscores the primary influence of socio-economic factors on the rural–urban disparities, with a secondary role for demographic and infrastructural aspects. However, education's impact was notably limited in this context. Insights on intra-district disparities infer that Khulna district exhibits significantly greater rural–urban disparities than the other two. The study also highlights the clustering of non-rural areas along major rivers. This research will assist rural planners and policy makers in understanding the specific rural dynamics of the study area, essential for tailoring fit-to-context development strategies. Moreover, the study provides a basis for classifying the region into clusters to streamline development priorities and resource allocation. Furthermore, the article presents a transferable methodology for evaluating rurality and delineating rural regions in different contexts.

Validation of the efficiency of arsenic mitigation strategies in southwestern region of Bangladesh and development of a cost-effective adsorbent to mitigate arsenic levels

World's highest arsenic (As) contamination is well-documented for the groundwater system of southwestern region (mainly Jashore district) of Bangladesh, where the majority of inhabitants are underprivileged. To mitigate As poisoning in southwestern Bangladesh, numerous steps have been taken so far by the government and non-governmental organizations (NGOs). Among them, digging deep tube wells and As removal by naturally deposited Fe(OH)3 species are being widely practiced in the contaminated areas. However, these actions have been left unmonitored for decades, making people unaware of this naturally occurring deadly poison in their drinking water. Hence, water samples (n = 63, both treated and untreated) and soil samples (n = 4) were collected from different spots in Jashore district to assess the safety level of drinking water and to understand the probable reasons for high As(III) contamination. About 93.7% of samples were found to contain As(III) above 10 μg/L; among them, 38% contained above 50 μg/L. The study shows that current As(III) removal strategies in the study area are ineffective. In this connection, a simple low-cost As(III) removal adsorbent is proposed that can be prepared with very cheap and locally available materials like iron sludge and charcoal. The adsorbent was characterized in terms of SEM, EDX, and XPS. The optimal dosage of the adsorbent was investigated for real-life application concerning several vital water quality parameters. The Fe–C adsorbent exhibited a maximum As(III) removal efficiency of 92% in real groundwater samples. The study will allow policymakers for informed decision-making regarding water body management as well as enable the local people to avail As-safe water in a way that aligns with their economic factors.

Salinity hazard drives the alteration of occupation, land use and ecosystem service in the coastal areas: Evidence from the south-western coastal region of Bangladesh

Understanding the salinity effects on the rural livelihood and ecosystems services are essential for policy implications and mitigations. Salinity-driven modulation in land use and land cover, community traditional occupations, and ecosystem service have been elucidated in the present investigation. The study was carried out in the south-western region of Bangladesh as a representative case using focus group discussions, questionnaire survey, and remote sensing techniques. The findings showed that salinity-induced land use changes seriously threatened ecosystem services, employment and livelihoods. Shrimp farming was found to have replaced the majority of agricultural and bare lands, which led to the poor locals losing their land. The increasing land transformation to shrimp ponds as a coping strategy with salinity was not reported to be a viable option as maximum marginal poor people were unable to run the capital-intensive shrimp aquaculture. Eventually, many rich people occupied the cropland for shrimp farming which forced the traditional farmers and fishermen to leave their job and sell their labor. Many of the traditional services derived from the ecosystems were drastically reduced or got lost. The ultimate effect on the traditional livelihoods of the communities increased vulnerability and reduced resilience. The findings could aid in formulating realistic policies and action for ensuring the future resilience of the community through an appropriate adaptation strategy, such as introducing salinity-tolerant crops and integrated farming to safeguard the interest of the poor farmers. Despite the geographical locality of the study, its implications are global given the identical salinity concerns in other emerging nations' coastal regions.

Compressive Behavior of Reconstituted Soils at High Initial Water Content: Case Study on South-Western Region Of Bangladesh

This study illustrates the experimental investigation of the effect of high initial water content on the compression behavior of reconstituted soil. For this attempt, disturbed soil samples were collected from two selected locations of the KUET campus, Khulna, Bangladesh. The reconstituted soils were prepared in the laboratory at different initial water content, ranging from 0.7 to 1.2 times their corresponding liquid limit. The main focus of this study was to investigate the compression behavior of reconstituted clays using oedometer tests. This work was complementary to the intrinsic compression line concept proposed by Burland (1990). In the laboratory, ASTM methods were followed to measure the initial properties of soils. Here, it can be observed that e - logσv compression curves show an inverse "S" shape as a result of resisting deformation due to pressure. Moreover, some important correlations were developed based on the initial void ratio and the void ratio at the liquid Limit e0/eL . It has been observed that the void index is a dominating parameter to normalize the squeezability characteristics at different initial water contents in the plastic post-yield regime. A non-unique relationship is obtained for different soils to express the intrinsic compression line concept. However, there is a proportional relationship between intrinsic compressibility and initial water contents or liquid limits. Journal of Engineering Science 14(1), 2023, 1-9

Uncovering the Morphological and Genetical Heterogeneity of Pyricularia oryzae (cooke) sacc. in Southwestern Region of Bangladesh

Significant yield losses are reported due to blast disease caused by Pyricularia oryzae across all rice growing areas of the world. Though, management strategies reduce disease significantly but blast epidemics are still common. This research was aimed to determine the variability among the 19 Pyricularia oryzae isolates of South-Western regions of Bangladesh. Morphological variability was determined based on nine morphological components like front mycelial color, reverse mycelial color, growth behavior, conidial length (μm), conidial width (μm), conidial color, radial growth at 12 days (mm), 14 days (mm) and 16 days (mm) after incubation. Cluster analysis considering nine morphological components showed five distinct groups. Front and reverse mycelial color, growth behavior and conidial length played more than 80% role in generating variation among the nine tested components. Higher genetic variation was also detected among the 19 isolates of P. oryzae. Here, larger numbers of amplified DNA fragments was formed by Primers UCB-155 which showed distinct polymorphism. Between two clusters, Cluster II consists of 18 isolates that were originated from different origin but having maximum 94% genetical similarity. Cluster I contain only one isolates PO-16. From pair wise distance matrix, maximum distance (80%) was found between PO-16 and PO-03 isolates and minimum distance (6%) was obtained between the isolates PO-11 and PO-12. Results of this experiment revealed that, higher genetic diversity among isolates of P. oryzae existed in the south western region of Bangladesh but there has no direct relation with genetic diversity and geographical origin.